The present invention relates to fasteners and more particularly to fasteners of a generally C-shaped configuration for use with a crimping tool.
Fasteners of the type herein contemplated comprise a length of metal wire bent into a generally C-shaped configuration to form an open ring fastener. The fasteners include spaced opposed curved free end portions interconnected by an arcuate central connecting portion.
The fasteners are typically a package comprising a row of abutting open ring fasteners. A structure which adheres the fasteners into the row comprises a tape that is bonded to the exterior surfaces of the connecting portions of the row of fasteners in order to package them.
There are several known crimping tools for bending these fasteners into a close ring formation. The U.S. Pat. No. 4,890,474, for example, discloses a clamping type tool for C-shaped fasteners. The premise behind these tools is to position a leading fastener of the fastener package, fed along a track feed of the tool, in an installation position wherein the elongated elements to be connected together are disposed between the spaced free ends thereof. The fastener is then crimped by a pair of pneumatically or manually operated closing jaws of the tool into a close ring formation in surrounding relation to the elongated elements. Because the ring configuration is to be transformed from a C-shape into a circular ring, special forming channels are provided in the front end of the upper and lower jaws. While the jaws are being closed, the free ends of the fastener are forced to slide along the forming channels in the jaws moving in a direction along the longitudinal extent of the fastener. These channels forcefully guide the fastener into the finished circular shape during closure. The channels are slightly offset so as the fastener is deformed, the free ends of the fastener are laterally deflected to move in a lapping relationship with respect to sections of the connecting portion. As the jaws are moved through the closing cycle, the connecting portion of the fastener comes into contact with a support structure that is designed to support the back of the fastener to ensure a circular shaped closure.
These fasteners have many different applications. They are well suited for joining together fabric, wire structures, such as marine lobster and crab traps, and various types of netting. They are particularly useful for constructing and maintaining Gabion structures that are used for earth retaining and erosion control projects. These structures must be assembled on site by first joining separate panels together into a box shape and then subsequently joining the box shaped units together into the desired structure which is then filled with river shingle or quarry stones.
Most all applications require that the fasteners have a minimum pull-open resistance. Due to this requirement, medium to high tensile wire is used to produce the fasteners. As the wire tensile force increases, there is a proportional increase in the force required to form the ring. For manual tools, this obviously makes the tool more difficult to operate. Moreover, because of this elevated force, associated frictional issues cause an unexpected high rate of erosion of the forming channels of the tool jaws. Components associated with the jaws"" closure such as jaw bushings and rollers are also affected along with the jaws. As the erosion progresses, the shape of the closed ring is affected. Normally when the ring shape is changed, a resultant decrease in ring pull open force is seen. There are some applications where the ring pull-open force needs to be controlled. The reason for the needed control is that the applied rings are many times part of a structural assembly, such as the Gabion structures noted above. These assemblies place a tensile force on the closed ring. When the ring reaches the tensile fail point, the structure being supported by the closed rings can fail.
There is a need to reduce the excessive wear on crimping tool components, particularly the jaws, which reduces the life cycle of the tool.
Along with the tool part wear issues, as the wear increases the rings being formed by the tool can be deformed during ring closure. A reduction of the force required by manual tool users to form the rings would also be beneficial.
It is an object of the present invention to meet the above-described need. In accordance with the principles of the present invention, this objective is achieved by providing a fastener for use with a crimping tool comprising a length of fastener metal wire bent into a generally C-shaped configuration to form an open ring fastener. The open ring fastener includes spaced opposed curved free end portions integrally interconnected by a central connecting portion. The open ring fastener is to be (1) positioned in an installation position with respect to elongated elements to be connected together disposed between the spaced opposed free ends thereof, and (2) crimped by a pair of closing jaws of the crimping tool into a close ring formation in surrounding relation to the elongated elements wherein the free ends are lapped with respect to sections of the connecting portion. The open ring fastener has a dry lubricant film on exterior surfaces of the curved free ends which slide with respect to the closing jaws when the open ring fastener is crimped so as to reduce the force required to effect the crimping movement.
As the fasteners are typically a package, the objective of the present invention is also achieved by providing a fastener package comprising a row of abutting open ring fasteners each formed of a length of fastener metal wire bent into a generally C-shaped configuration that includes spaced opposed curved free end portions integrally interconnected by a central connecting portion. Structure adhering the row of open ring fasteners in abutting relation so as to be fed in the direction of the row along a crimping tool feed track to present a leading open ring fastener for crimping between closing crimping tool jaws into a closed ring formation wherein the free ends are lapped with respect to sections of the connecting portion. The row of open ring fasteners has a dry lubricant film on exterior surfaces of the curved free ends of the fasteners of the row.
The present invention also provides an apparatus for applying a lubricant to an adhered row of abutting open ring fasteners cut into predetermined lengths made in a mechanism which moves the row along a predetermined final path in an elevated temperature condition. The apparatus comprises a guide structure extending from the path to guide the adhered row of abutting open ring fasteners past a lubricant applying station. A lubricant applying assembly at the lubricant applying station has structure to apply a wet solution of a lubricant as a thin film on exterior surfaces of a pair of spaced curved free ends of the ring fasteners as they move past the assembly while still at the elevated temperature condition which aids in drying the lubricant.
Another aspect of the invention is providing a method of making fastener packages comprising: moving an adhered row of abutting open ring fasteners cut into predetermined lengths past a lubricant applying station, applying a wet solution of a lubricant as a thin film on exterior surfaces of a pair of spaced curved free ends of the ring fasteners as they move past the lubricant applying station, and causing the wet solution to dry on the applied surfaces of the fasteners.
These and other objects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, the principles of this invention.